The present invention relates to an apparatus for cleaning the interior of such an enclosure as a tank by jets of liquid under high pressure.
Tanks in various industries, such as for brewage or fermentation, are generally cleaned by an apparatus which causes a nozzle housing into rotation about its axis while rotating nozzles about a predetermined axis to jet liquid under high pressure to a uniform distribution. Both the rotation of the housing and that of the nozzles share the pressure of the liquid. For example, the housing is driven by an impeller disposed in an internal passageway of the apparatus and the nozzles are moved each in the opposite direction to the ejection of liquid therefrom based on the reaction to the ejection.
However, the force of ejection from the nozzles is reduced by a proportion consumed by the rotation of the housing and that of the nozzles. Also, the nozzles are individually angled 90.degree. so as to achieve the necessary reaction for rotation so that the resulting stream of liquid from each nozzle does not converge but becomes scattered. Meanwhile, because the rotation speeds of the housing and nozzles are commonly proportional to the amount of pressurized liquid supply, it is impossible to control only the pressure of liquid jets from the nozzles while maintaining the rotation speeds at values optimum for cleaning. This limits the applicable range of such a cleaning apparatus.
An implement heretofore known for eliminating this problem comprises a damper or the like which is installed within the housing to apply a predetermined torque to the housing. This implement suffers from severe drawbacks, however, that the apparatus as a whole grows bulky, intricate and, accordingly, expensive, and that the apparatus is inapplicable to food industry due to possible leakage of oil out of the damper or the like.